<nz-tabset [nzTabPosition]="'top'" [nzType]="'card'" 
[nzSelectedIndex]="index"
(nzSelectChange)="selectedIndex($event)"
>
  <nz-tab>
    <ng-template #nzTabHeading>
      系统消息
    </ng-template>
  </nz-tab>
  <nz-tab>
    <ng-template #nzTabHeading>
      系统公告
    </ng-template>
  </nz-tab>
</nz-tabset>
  <!-- 系统消息 -->
  <app-system-info *ngIf="index == 0"></app-system-info>
  <!-- 系统公告 -->
  <app-system-placard *ngIf="index == 1"></app-system-placard>